The most extraordinary moist Chocolate Chip Cake made by preheating oven to 350°F greasing flouring and lining two 9-inch pans whisking 3 cups flour 2 1/2 tsp baking powder and 1/2 tsp salt setting aside tossing 1 cup mini chocolate chips with 1 tbsp flour setting aside beating 1 cup softened butter and 1 3/4 cups sugar 3 minutes light and fluffy adding 4 room temperature eggs one at a time then vanilla and 1/2 cup room temperature sour cream on low alternating flour mixture in 3 additions with 1 cup room temperature milk in 2 additions beginning and ending with flour gently folding flour-coated chips dividing evenly baking 28 to 32 minutes until toothpick clean cooling 10 minutes then on racks then beating 1 1/2 cups room temperature butter 3 minutes adding 5 to 6 cups sifted powdered sugar 3 to 4 tbsp cream vanilla and salt beating medium-high 3 minutes fluffy stirring in 1/2 cup mini chips by hand assembling with generous frosting between layers and exterior. A completely perfect mini chip vanilla sour cream birthday cake recipe.